Machine for applying liquid material



Aug. 2, 1955 B. G. INNERFIELD 2,714,267

/ MACHINE FOR APPLYING LIQUID MATERIAL .Filed Nov. 8, 1952 s Sheets-Sheet 1 BARRY G. INN ERFIELD INVENTOR.

1955 B. G. INNERFIELD 2,714,267

MACHINE FOR APPLYING LIQUID MATERIAL.

Filed Nov. 8, 1952 5 Sheets-Sheet 2 /I l// A rum.

BARRY G IN NERFIELD INVENTOR.

g- 1955 B. G. INNERFIELD 2,7 4, 7

MACHINE FOR APPLYING LIQUID MATERIAL Filed Nov. 8, 1952 3 Sheets-Sheet 3 BARRY GJNNERHELD JNVENTOR.

United States Patent MACHINE FOR APPlLYlNG LIQUID MATERIAL Barry Gartner Innertield, Brooklyn, N. Y.

Application November 8, 1952, Serial No. 319,467

13 Claims. (Cl. 41-1) This invention relates to a method and means for applying a coating to the surface of a base material; said invention being particularly useful for the deposition of electrical resistance inks upon base materials and printed circuit supporting surfaces.

It is an object of this invention to provide a method and means for the application of a coating of such materials as inks, paints, varnishes, lacquers, etc., upon a base or supporting surface in a simple, efficient and effective manner wherein the quantity, thickness and configuration of the coating may be precisely controlled.

It is a more particular object of this invention to pro vide a method and means for the deposition of a layer of electrical resistance material in such form as to comprise an electrical resistance circuit element upon a base support as well as upon printed circuit bearing surfaces in which the resistance of the deposited elements are maintained within close tolerances by the control of the quantity and configuration of the deposit as it is applied.

A further object of this invention is to provide a method and means for the deposition of a coating material upon a base surface which is accurately reproducible within close tolerances.

Other and further objects of this invention will become apparent from the description thereof contained in the annexed specifications, or will otherwise become obvious. It will be understood that the invention here disclosed may be employed for other purposes to which the structure and arrangement are adapted.

As shown in the accompanying drawings,

Figure 1 is a front elevational view of an apparatus in accordance with the present invention.

Figure 2 is a plan view thereof, a portion of the press head being broken away for the purpose of clarity.

Figure 3 is a bottom view of a mold plate in accordance with the present invention.

Figure 4 is a cross section of Figure 3 taken along line 4-4 thereof.

Figure 5 is a cross section of a supporting surface such as a sheet bearing a deposit in accordance with the present invention.

Figure 6 is a cross section of a portion of the mold plate taken along lines 66 of Figure 2.

Figure 7 is a cross section of a mold plate in accordance with the present invention showing a modified form of a liquid feed means.

As shown in Figure 1, wherein is illustrated an embodiment of the present invention, an apparatus useful in practicing the invention is comprised of a suitable support or main frame 10 upon which is mounted a press bed 11 suitably supported by transverse members 12 carried by the longitudinal supporting members 13 of the frame. Cylindrical rolls .l i and 15 are rotatably supported in journal bearings 16 and 17 secured to the main frame 10. Cylinders 14 and 15 carry an endless belt or conveyor 18 which is adapted to transport and position the base material to which the coating or deposit is to be applied as will more clearly appear hereafter. A suitable motor 19 is operatively connected with cylinder 15 by means of belt 28 and pulleys 2i) and 21. A suitable speed reducing gear train 22 may be interposed between the motor 19 and drive belt 23 for the purpose of provlding 2,714,267 Patented Aug. 2, 1955 a suitable conveyor speed. A suitable press 23 which may be of conventional design is located along the path of travel of conveyor 18. The press 234 is provided with a reciprocating stem 27 which carries mold plate 25 thus effecting the raising and lowering of said mold plate 25. It will be noted that as conveyor belt 18 travels it transports base material 3b to a position underneath mold plate 25 and over press bed plate ill, at which point it is presented for the operation of the press; said sheet of base or supporting material being thereupon re moved by the continued movement of the conveyor, which simultaneously presents the next sheet to be operated upon by the press. It will be understood that suitable control means for starting and stopping the conveyor belt so as to permit the press to operate upon the base material as it is positioned thereunder are also provided although not shown. Such control means may be conventional.

It will also be noted that the conveyor belt 18 is provided with stop elements 26 suitably positioned so as to locate the supporting material 30 for accurate registration as it is presented to the operation of the: press. Supporting material 3t) may be any material to which it is desired to apply a coating such as paper, plastic, ceramic, glass or metal and may be in the form of a sheet to which a printed electrically conductive circuit has been applied by conventional methods and upon which it is desired to deposit electrical resistance elements of specific values at given points. Although the embodiment of the invention herein illustrated shows the deposition of the coating material upon flat sheets, it will be understood that similar suitably formed mold plate means may be utilized, for coating or depositing upon cylindrical or other irregular surfaces without departing from the spirit or .scope of this invention. It will also be understood that other suitable base material feed means may be utilized for this purpose. The apparatus may be hand fed if desired.

The embodiment of the invention herein disclosed more particularly illustrates the invention as employed for the deposition of electric resistance material upon a supporting surface of sheet material such as a printed circuit. It will be understood, however, that the invention may be utilized for depositing other materials such as inks, paints or lacquers for the production of color cards or may be used generally for coating or printing applications.

In the application of electric resistance material to supporting surfaces such as, for example, a printed circuit, it is desirable to utilize a resistance material in liquid or ink form which is usually comprised of finely divided carbon dispersed in a suitable liquid carrier. The electric resistance of the ultimate deposited resistance element is determined by the formulation of the ink and the quantity thereof which is deposited as well as its geometric configuration.

The resistance ink may be deposited upon an insulatin surface which may thereafter be interconnected with other electric circuit elements or, as in the case of printed circuits which are comprised of conductive films or foils carried by a support of insulating material, the ink may be directly deposited upon the circuit outlines formed by such films or foils to interconnect suitable portions thereof and to provide the desired electrical resistance therebetween. After the deposition of such ink has been accomplished the ink may be dried, heat cured or otherwise fixed, as is well known to those skilled in the art. In order to achieve resistance elements Within narrow tolerances it is essential that the quantity and geometric configuration of the resistance material deposited for each resistor be precisely controlled. Figure 3 illustrates a mold plate in accordance with the present invention which is adapted for the simultaneous deposition of six resistance elements or resistors. It will be understood, however, that the device may be utilized for the deposition of individual resistors or any number and that the configuration and location of said elements may be'varied in accordance with the requirement of the particular application.

As may be seen from Figures 3 and 4, mold plate 25 is provided with a plurality of mold recesses or cavities 31 as may be more clearly seen from Figure 4, These mold recesses or cavities 31 may be formed by securing an independent face plate 29 to the under-surface of mold plate 25, cavities 31 being formed in face plate 29 by providing suitable cut out portions in said face plate, It will be understood however that such cavities 31 may be directry formed in plate 25 by engraving or other suitable methods.

Each of the mold recesses or cavities 31 is provided with two apertures, said apertures comprising an inlet port 32 and a relief or scavenging port 33 for each of said cavities. Each of said ports has mounted therein a valve 34 as is more particularly illustrated in Figure 6. The valve may be of conventional form adapted to be normally spring biased to closed position and to be opened by the operation of valve stem 35 when the operating end of said valve stem is pressed inwardly toward the body of the valve.

Thus as shown in Figure 6, the valve structure is identical in each of the valves and may be of conventional design and is comprised of a plug 37 threadedly engaged with complementary threads formed on the walls of ports 33 and 34 as shown at 36. Said plug 37 is centrally bored to provide a fluid passage therethrough. A valve stem 35 extending through the bore and spaced from the walls thereof is provided with valve member 38 which seats upon the upper surface 39 of plug 37 forming a valve seat therefor, and which may be provided as shown at 24 with a suitable sealing gasket. Valve member 38 is maintained in sealing contact with the said valve seat by means of spiral spring 40 which is provided with a retaining cap element 41. The lower end 42 of stem 35 extends beyond the surface of face plate 29 and cornprises a valve operating member which, when pressed upwardly, raises valve member 38 from its seat against the biasing action of spring 40, thereby opening the valve and permitting the passage of fluid through the bore in plug 37. Thus in the case of inlet port 32 the operation of this activating member 42 permits fluid to enter cavity 7 31 whereas in the case of scavenging or relief port 33 the operation of the activating member permits air and fluid to escape from said cavity through the valve. controlling the inlet port 32 will therefore be referred to as the inlet valve and the valve in the scavenging or relief port as the scavenging or relief valve.

Referring again to Figures 1, 4 and 5, it will be seen that when mold plate 25 is moved downwardly valve stems 35 contact the surface of the material 30 upon which the deposit is to be made and that both inlet valve 32 and scavenging or relief valve 33 are simultaneously opened asthe operative surface of mold plate 25 contacts the surface of the material upon which the deposit is to be made.

The inlet end of each valve 32 is connected to a reservoir 43 of liquid or resistance ink by a suitable feed conduit 44. Reservoir 43 is provided with a conduit 45 connecting it to a suitable source of compressed air not shown, for the purpose of applying a pressure upon the liquid contained in the reservoir to thereby force it through feed conduit 44 and into the inlet port 32. The entry of liquid into the mold recess proper is controlled by means of the inlet valve associated therewith. The operation of said valve by contact of valve operating member 42 with the supporting surface upon which the deposit is to be made as the mold plate abuts with said surface, permits the liquid to be forced into recess or cavity 31. It will also be noted that the contact of the The valve mold plate with the material surface simultaneously operates valve operating member 42 in the scavenging or relief valve 33, thereby permitting the air entrapped in said cavity to escape therefrom through said relief port, and thus relieving the cavity of such entrapped air. The mold cavity is thus readily and completely filled with the liquid. In order to be additionally assured that the cavity is completely filled with the resistive ink or other liquid which it is desired to apply, contact between the mold plate and the material surface is maintained somewhat longer than is necessary to fill the cavity, thus permitting some of the resistive ink or other coating material to be forced through scavenging valve 33. In this manner the cavity is completely relieved of all air and .1 also of the initial flow of coating material which may the supporting surface is broken.

have entrapped air bubbles, and pfirovision is made for completely filling the cavity with the desired liquid. When the cavity has been thus completely filled mold plate 25 is reciprocated upwardly and the contact be- -2- tween the operative surface of said mold plate and the material surface is broken, both the inlet and relief valves are immediately and automatically closed by the spring biased action of the valve stems thereby cutting off the flow of ink from the reservoir and preventing the backflow of any ink which has passed through the scavenging valve 33 into its associated port. The deposit of ink or coating material thus achieved is illustrated in Figure 5 and comprises the exact volume of fluid required to fill the mold cavity and is precisely of the same configuration as that cavity, particularly with respect to the area covered thereby. The quantity of resistance ink or coating material thus deposited is precisely metered in that all air pockets have been eliminated therefrom. Resistors 46 deposited upon a supporting surface 39 are illustrated in Figures 1 and 5. The base material 30 is comprised of electrical insulation to which conductors 47, which may be of metallic foil, have been applied. Resistors 46 are printed thereon and serve to provide suitable electrically resistive paths therebetween.

The scavenging action of the arrangement is particularly important in the deposition of liquids which include volatile materials. Some of the liquid introduced into the cavity wets or may adhere to the walls of the cavity and is thus exposed to the atmosphere between operations whereby such volatile materials may escape causing a change in viscosity or concentration. In such applications as printing of resistors such change may significantly alter the characteristics of the deposited ele-' ment. By forcing a fresh supply of material through the cavity and out through the relief port the interior of the cavity is washed or scavenged of the old material thus insuring that the deposited element will be free of materials which may have significantly been altered in composition or which might significantly alter the characteristics of the deposited element. The ink or material which is forced into the relief or scavenging port is prevented from returning into the cavity by the automatic closing of its associated valve as contact with A suitable conduit may be connected to the scavenging port to carry away this material to a suitable vessel. ince the scavenging or relief port 33 is open to the atmosphere as the liquid is injected into the cavity, less pressure is required upon the supply of material and a shorter dwell time for contact between the operative face of the mold plate and the supporting material is practicable. Tie shorter dwell period and lower pressure is particularly significant since the possibility of escape of material around the edges of the cavity at points of contact with the supporting surface is thus lagrgely eliminated and permits the deposition of elements having sharply defined and precise marginal edges which are accurately duplicated with each impression.

Figure 7 illustrates a modified form of mold plate in cross section wherein the inlet and scavenging ports 32 and 33 are provided with laterally extending openings 48 for convenience in connection to a supply source and carrying away the scavenged air and liquid.

I have here shown and described a preferred embodiment of my invention. It will be apparent, however, that this invention is not limited to this embodiment, and that many changes, additions and modifications can be made in connection therewith without departing from the spirit and scope of the invention as herein disclosed and hereafter claimed.

Having disclosed my invention, what I claim as new and desire to secure by Letters Patent is:

1. A device for depositing a liquid upon a surface comprising a plate adapted to contact the surface to be treated, a depression formed in the operative face of said plate. an inlet port in communication with said depression, liquid supply means operatively connected with said inlet port, a liquid flow control valve interposed between said supply means and said depression and an additional port in communication with said depression, whereby entrapped air and liquid introduced into said depression may be permitted to escape therefrom.

2. A device for depositing a liquid upon a surface comprising a plate adapted to contact the surface to be treated, a depression formed in the operative face of said plate, an inlet port and a vrelief port in communica tion with said depression, liquid supply means operatively connected to said inlet port, valve means interposed between said inlet port and said supply means adapted to control the flow of liquid into said depression and additional valve means associated with said relief port adapted to permit the escape of liquid and entrapped air therefrom.

3. A device for depositing a liquid upon a surface comprising a plate adapted to contact the surface to be treated, a depression formed in the operative face of said plate, an inlet port and a relief port in communication with said depression, liquid supply means operatively connected to said inlet port, valve means interposed between said supply means and said inlet port adapted to control the flow of liquid into said depression and valve means, simultaneously operable with said first valve means, interposed between said relief port and the atmosphere adapted to permit the passage of air and liquid from said depression.

4. A device for depositing a liquid upon a surface comprising a plate adapted to contact the surface to be treated, a depression formed in the operative face of said plate, an inlet port and a relief port in communication with said depression, liquid supply means operatively connected with said inlet port, normally closed valve means operatively associated with each of said ports.

5. A device for depositing a liquid upon a surface comprising a plate adapted to contact the surface to be treated, a depression formed in the operative face of said plate, said plate being provided with an inlet port and a relief port in communication with said depression, liquid supply means operatively connected with said inlet port, valves located within each of said ports, a valve operating member extending from each of said valves into said depression and beyond the operative face of said plate whereby said valves are adapted to be operated during contact with said surface.

6. In a device for depositing a liquid upon a surface having a plate adapted to contact the surface to be treated and a depression formed in the operative face thereof supplied with liquid through a valve controlled inlet port, a relief port provided in said plate in communication with said depression, valve means operatively positioned in said relief port selectively controlling the passage of air and liquid from said depression during contact of said plate with said surface and preventing the return flow of said excess liquid upon the separation of said plate from said surface.

7. In a device for depositing a liquid upon a surface, said device having a plate adapted to contact the surface to be treated, provided with a recess formed in the operai tive face thereof and adapted to be filled with the liquid to be applied, a relief port in communication with said recess, valve means carried by said outlet port, a valve operating member extending from said valve through said recess and beyond the operative face of said plate whereby said valve is adapted to be operated during contact of said plate with said surface to permit the passage of air and liquid from said depression.

8. A device for depositing a predetermined quantity of liquid in a predetermined pattern upon a surface comprising a plate adapted to contact the surface to be treated, a depression formed in the operative face of said plate of the depth and configuration desired, an. inlet port and a relief port in communication with said depression, liquid supply means operatively connected to said inlet port, valve means interposed between said supply means and said inlet port to control the flow of liquid into said depression, said relief port being adapted to relieve said depression of air and to permit the escape of liquid therethrough.

9. in a device for applying a predetermined quantity of coating liquid to a surface, a plate having a cavity in the operative face thereof, said cavity being of a predeterrniued depth and defined by confining walls formed in the configuration of a predetermined pattern, apertures in communication with the interior of said cavity, a control valve mounted in one of said apertures, liquid supply means connected to the inlet of said valve, a valve operating member at the outlet of said valve extending into said cavity and beyond the operative face of said plate, whereby said valve is adapted to be operated during contact with the surface to permit the flow of liquid into said depression, a second valve mounted in the other of said apertures adapted to permit the passage of air and liquid from said cavity as said liquid is introduced therein.

10. The device according to claim 9 wherein said sec ond valve is provided with a valve operating member extending through said cavity and beyond the operative face of said plate whereby said valve is adapted to be operated during contact with said surface.

11. The device according to claim 9 wherein said valves are simultaneously operated.

12. A device for depositing a resistance ink upon a supporting surface to form an electrical resistor thereon which comprises a plate adapted to contact said surface and provided with a recess in the operative face thereof of the configuration of the deposit to be made and adapted to be filled with said ink, an inlet port formed in said plate in communication with said recess, ink supply means operatively connected with said inlet port, an ink flow control valve interposed between said supply means and said recess, an additional port provided in communication with said depression.

13. A device for the deposition of a resistance ink upon a supporting surface to form an electrical resistor thereon which comprises a plate adapted to contact said surface, said plate being provided with a recess in the operative face thereof of the configuration of the deposit to be made and adapted to be filled with said ink, an inlet port provided in said plate in communication with said recess, ink supply means operatively connected with said inlet port, an ink flow control valve interposed between said supply means and said recess, an additional port provided in said plate in communication with said recess, valve means carried by said latter port adapted to permit the passage of air and ink from said recess.

References Cited in the file of this patent UNITED STATES PATENTS 

